Reducing latency in OFDMA using front ends with adaptive linearity

Abstract

Embodiments herein describe assigning different linearity operating points of a front end of a radio to groups of user devices when transmitting data using OFDMA. That is, when transmitting a PPDU to a first group of user devices, an access point (AP) may set the front end of the radio to a lower linearity operating point than when transmitting a PPDU to a second group of user devices. Using a higher linearity operating point can increase the data rate used to transmit the PPDU—e.g., the AP can use a higher modulation coding scheme (MCS). This can reduce the time the PPDUs have to wait in a queue before being transmitted.

We claim: 
     
       1. A method, comprising:
 grouping a plurality of devices associated with an access point into at least a first group and a second group as part of orthogonal frequency-division multiple access (OFDMA) based on portions of the plurality of devices being at least one of in a similar area or a similar distance from the access point, wherein grouping the plurality of devices comprises determining a location of each of the plurality of devices relative to the access point based on a link budget, supported data rates, and a modulation coding scheme (MCS) level for each of the plurality of devices, and wherein the first group corresponds to a different linearity operating point of a front end in the access point than the second group; 
 transmitting a first physical layer protocol data unit (PPDU) for the first group using a first linearity operating point of the front end; and 
 transmitting a second PPDU for the second group using a second linearity operating point of the front end. 
 
     
     
       2. The method of  claim 1 , wherein the first PPDU contains data corresponding to resource units (RUs) for the first group, wherein the second PPDU contains data corresponding to RUs for the second group, wherein both the first group and the second group comprises multiple ones of the plurality of devices. 
     
     
       3. The method of  claim 1 , wherein the front end operates with a higher operating voltage at the first linearity operating point than the second linearity operating point. 
     
     
       4. The method of  claim 1 , wherein the first group contains devices that are further from the access point than devices in the second group. 
     
     
       5. The method of  claim 1 , wherein transmitting the first PPDU for the first group using the first linearity operating point of the front end results in the first PPDU being transmitted at a greater MCS level than if the second linearity operating point of the front end were used. 
     
     
       6. A non-transitory computer readable medium having program instructions embodied therewith, the program instructions executable by a processor to perform an operation, the operation comprising:
 receiving a grouping of a plurality of devices associated with an access point into at least a first group and a second group as part of OFDMA, wherein the grouping of the plurality of devices is performed by determining a location of each of the plurality of devices relative to the access point based on a link budget, supported data rates, and a modulation coding scheme (MCS) level for each of the plurality of devices, and wherein the grouping of the plurality of devices is further based on portions of the plurality of devices being at least one of in a similar area or a similar distance from the access point, and wherein the first group corresponds to a different linearity operating point of a front end in the access point than the second group; 
 transmitting a first physical layer protocol data unit (PPDU) for the first group using a first linearity operating point of the front end; and 
 transmitting a second PPDU for the second group using a second linearity operating point of the front end. 
 
     
     
       7. The non-transitory computer readable medium of  claim 6 , wherein the first PPDU contains data corresponding to resource units (RUs) for the first group, wherein the second PPDU contains data corresponding to RUs for the second group, wherein both the first group and the second group comprises multiple ones of the plurality of devices. 
     
     
       8. The non-transitory computer readable medium of  claim 6 , wherein the front end operates with a higher operating voltage at the first linearity operating point than the second linearity operating point. 
     
     
       9. The non-transitory computer readable medium of  claim 6 , wherein the first group contains devices that are further from the access point than devices in the second group. 
     
     
       10. The non-transitory computer readable medium of  claim 6 , wherein transmitting the first PPDU for the first group using the first linearity operating point of the front end results in the first PPDU being transmitted at a greater MCS level than if the second linearity operating point of the front end were used. 
     
     
       11. An access point, comprising:
 a radio comprising a front end; and 
 a scheduler configured to:
 receive a grouping of a plurality of devices associated with the access point into at least a first group and a second group as part of OFDMA, wherein the grouping of the plurality of devices is performed by determining a location of each of the plurality of devices relative to the access point based on a link budget, supported data rates, and a modulation coding scheme (MCS) level for each of the plurality of devices, and wherein the grouping of the plurality of devices is further based on portions of the plurality of devices being at least one of in a similar area or a similar distance from the access point, and wherein the first group corresponds to a different linearity operating point of a front end in the access point than the second group, 
 transmit a first physical layer protocol data unit (PPDU) for the first group using a first linearity operating point of the front end, and 
 transmit a second PPDU for the second group using a second linearity operating point of the front end. 
 
 
     
     
       12. The access point of  claim 11 , wherein the first PPDU contains data corresponding to resource units (RUs) for the first group, wherein the second PPDU contains data corresponding to RUs for the second group, wherein both the first group and the second group comprises multiple ones of the plurality of devices. 
     
     
       13. The access point of  claim 11 , wherein the front end operates with a higher operating voltage at the first linearity operating point than the second linearity operating point. 
     
     
       14. The access point of  claim 11 , wherein the first group contains devices that are further from the access point than devices in the second group. 
     
     
       15. The access point of  claim 11 , wherein transmitting the first PPDU for the first group using the first linearity operating point of the front end results in the first PPDU being transmitted at a greater modulation coding scheme level than if the second linearity operating point of the front end were used. 
     
     
       16. The access point of  claim 11 , wherein the front end comprises circuitry coupled to an antenna of the access point configured to communicate with the plurality of devices. 
     
     
       17. The access point of  claim 16 , wherein the front end comprises at least one amplifier and mixer.